The architects of the campaign finance reform act, which was partly overturned in the lower courts, have asked Supreme Court to suspend that judgment until it has a chance to rule.

Democrat candidates are already raising money

Last week the US district court, in a split decision, said that some provisions of the new campaign finance law, which was expected to take effect in time for the 2004 presidential election, violate the free speech provisions of the US constitution.

Now Senator John McCain, the author of that bill, wants the Supreme Court to stay the implementation of that decision until it has a chance to review the legislation itself in the autumn.

"We don't feel that's fair to the campaigns and the candidates to operate under three different sets of rules," he said.

Otherwise, he fears, Democrats and Republicans organising for next year's election would begin raising "soft money" from corporations and trade unions.

The ban on the use of such money for campaign advertising is at the centrepiece of the campaign finance reform.

But with the Democratic campaign for the presidential nomination in full swing, and President Bush's allies about to launch a fund-raising tour, the matter is becoming increasingly urgent.

Already press reports suggest that the Democrats are planning to set up a separate political action committee to raise extra soft money funds from unions to fight the next election.

Disputed court judgment

Senator McCain said he was confident that the Supreme Court would uphold the campaign finance law when it considers it this autumn.

Senator McCain; author of campaign finance reform

But he also argued that the lower court had upheld "80% to 90% of the campaign finance reform law."

In a complex decision, the lower court did uphold the ban on soft money being spent on political advertising.

Such "attack ads" have often targeted political candidates for their stand on such issues as abortion or gun control.

But it allowed parties to raise money from special interest groups to pay for general electoral activities like voter registration or get-out-the-vote campaigns.

Campaign reformers fear that this loophole could be exploited through weak enforcement by the Federal Election Commission.

And they argue that Congress has been tainted by the public belief that companies who contribute heavily to political campaigns get favours in return.

Money and politics

Money has increasingly become the key factor in US elections, which cost more than $1bn in the 2000 contest alone.

The uncertainty over the campaign finance rules could fundamentally change the character of the 2004 election.

President Bush is already expected to have a huge advantage in fund-raising, which would be magnified many times if his campaign was allowed to raise money from corporations as well.

Under the reform bill, the presidential campaigns were supposed to be financed from individual donations which were limited to $2,000 per person.